Inlet arrangement- Rapid Sand Gravity filters

[Lan123]

In a rapid sand filtration system what is the best influent distribution arrangment to split influent to each individual filter unit?

(a) Combination of Butterfly valves and inlet pipes.

(b) Channels and sluice/weir gates.

Even if the latter is the preferrred method, can method (a) be still used? If so how do we make sure that the alum flocs do not rupture as they enter the filters? Can this be achieved by maintaining the Reynolds number within the laminar region.

Thanks in advance.

 

[bimr]

Method (a) is more common with pressure filters. Method (b) is more common with gravity filters, especially after clarification with multiple filters.

Either method will work. You do not have to worry about the Reynolds number.

As a practical matter, the effects of pressure surges, flow rate changes, etc. have a greater effect on the effluent quality.